Treatment of rubber



Patented July 3, 1945 T T v Q 'Serial No. 4 9[,39 7 f 1 I -tyrants. (01.260 -783) This invention relates to thepreservationofratio'eof}the.tensile iistrengths before and alter rubberandmore-parti'cularly to theus offa new agingwas; I class of ageresisters'forrubber'. 5 I

Many'materials have beenemployed-toimprove e I the resistance-of rubberto deterioration'through 5 Egg? f aging. The relative effectivenessof-such matee rials as well as theirspecific effectasantioxi a J' W "p fi dents, flex'i'mprovers;etciyaries'greatly; Bythe rhenyl-s-naphtlyiamine 10o I 97 present invention a new a r g fiTetrahydro-l,4-naphthoqu1nono v 100 135 age resisters is provided forrubber. 10 i It is known that p-benzoquinone and c0nju In addition tothe parent butadiene-1,3 emgated dienes, such as butadiene-1,3, react togive Ployed u fdregqing example, compounds polycyclic compounds. Forexample, p-benzoquiv which One or more, of t hydregens i replaced noneand butadiene-L3 react as follows: by a substituent group y s e usedl5ther exampleslare' isoprene; l- -m'ethyl-lB-penta- H r diene;1,3-pentadiene and. 1-phenyl-l,3 -butao 0 diene.. I H H 0 Various other1,4-quinones may also be used,

including 1,4-naphthoquinone, 1,4-phenanthra- CH2=C-C:CH2 ll quinone and1,4-anthraquinone. Also, the quik nones may contain various substituentssuch as I a I o alkyl, aryl, aralkyl, halogen, hydroxyl and simo a bilar groups, such substituted compounds being H equivalents of theparent compounds for purposes The resulting product is tetrahydro-l l-nahthoof this inventionquinone; more exactly, .4a,5,8,8a-tetrahyd :o-1,4-Tetrahydro'l4'naphthoqmnones obtamed as m naphthoqui n This pale yellowcwstab Example 1 will further react with butadienes at line materialmelting at 55-60 C. and extremely Somewhat elevated temperatures, t0 P csoluble in benzene. The preparation of this mapolyhydroanthmquinones,for example, at a u terial is illustrated by the following example: 7 AtSuch temperatures. the reaction 1s v carried out under pressure in orderto prevent Emmple 1 loss of material. Alternatively, One mol of theFifty-five grams of p-benzoquinone were suspen q in ay be a t d undersimilar pended in 100 cc. of benzene and butadiene gas conditions oftemperature and pressure with two was bubbled into the mixture until thebottle and mols of a 1,3-butadiene. Thus,- p-benzoqumone contentsincreased inweight by about 32-35 and butadiene-l,3 will yield theoctohydroangrams. The mixture was then allowed to stand thraquinone ofthe following formula: for 5 days at room temperature with occasionalshaking. The benzoquinone slowly disappeared, H H O H H having gonecompletely into solution after 2 days. 40 k I The benzenewas thendistilled from the solution g A and the liquid residue was cooled. Whencrys- H CH tallization began, several volumes of petroleum g ether wereadded. The crystals were filtered off j r and washed with more petroleumether. Seventy- 1 Y eight grams of gray crystals were obtained, H H H Hamounting to 96% of the theoretical yield. I H

This material was incorporated into rubber in p The products obtainedby'the reaction of 1,4-

accordance with a standard testing formula and quinones and1,3-butadienes may be designated was aged for 6 days in an oxygen bombat C. 50 tetrahydr polycyclic quinones. In accordance and lb. pressure.A control usin phenyl-. with this terminology, theoctahydroanthraquibeta-naphthylamine, a commercial age resister, noneformed by the reaction of one mol of p-benwas tested under comparablconditions. .The zoquinone with two mols of butadiene-1,3 may beonstrated by the following example:

regarded as a di(tetrahydro) polycyclic quinone. Further examples ofsuch tetrahydro polycyclic quinones are6-methyl-4a,5,8,8a-tetrahydronaphthoquinone-dimethyl-4a,8,8a-trihydronaphthoquinone 5-methy1-4a,5,8,8a-tetrahydronaphthoquinone5-phenyl-4a,5,8,8a-tetrahydronaphthoquinone.

Any such tetrahydro polycyclic quinones may be incorporated into rubberas age resisters.

The tetrahydro polycyclic quinones of the invention are readilyconverted into the corresponding hydroquinones by warming with a traceof hydrogen bromide as a catalyst. This is dem- Example 2 Twenty-sixgrams of 4a.,5,8,.8a'-tetrahydro-1,4- naphthoquinone were dissolved in'7 5 cc. of acetic acid. The solution was warmed to 80 C. and one dropof concentrated hydrobromic acid was added. A vigorous exothermicreaction occurred,

the temperature running up to 110-115 C. while The hydroquinone formedis not quite as good an age resister as the quinone, probably due to thehigher melting point and lower solubility in rubber of the former, butit is still somewhat better than phenyl-beta-naphthylamine.

What is claimed is:

1. A method of treating rubber which comprises vulcanizing it in thepresence of a tetrahydro polycyclic quinone of condensed ring structure.

2. A method of treating rubber which comprises vulcanizing it in-thepresence of a tetrahydronaphthoquinone.

3. A method of treating rubber which comprises vulcanizing it in thepresence of an octahydroanthraquinone.

4. A method of treating rubber which comprises vulcanizing it in thepresence of 4a,5,8,8atetrahydronaphtho quinone- 1,4.

5. A rubber product which has been vulcanized in the presence of atetrahydro polycyclic quinone of condensed ring structure.

6. A rubber product which has been vulcanized in the presence of atetrahydronaphthoquinone.

7. A rubber product which has been vulcanized in the presence of anoctahydroanthraquinone.

8. A rubber product which has been vulcanized in the presence of4a,5,8,8a-tetrahydronaphthoquinone-1,4. p

I RUTH P. SCOTT,

Executria: of the Last Will and Testament of Winfield Scott, Deceased.

